1. Field of the Disclosure
The present invention relates to an optical fiber.
2. Description of the Related Art
Along with the recent tremendous growth in Internet traffic, the power of the light transmitted through a single optical fiber has also increased; therefore, nonlinear optical phenomena in optical fibers and fiber fuses have become major problems. An effective solution to the above problems is to increase the effective core area (Aeff) of the optical fiber. However, when performing single-mode transmission at a communication waveband by using a conventional solid optical fiber that has an increased effective core area, a problem occurs in that macrobending losses and microbending losses are increased. A microbending loss is defined as an increase in the transmission loss due to a minute bend in an optical fiber that occurs, when lateral pressure is applied to the optical fiber, by fine bumps, etc., on the surface of a lateral-pressure applying object (for example, a bobbin).
To decrease the macrobending loss and the microbending loss that occur when single-mode transmission is performed with the effective core area being increased, methods are proposed that use trench refractive index profiles (Japanese Patent Application Laid-open No. 2006-78543, S Matsuo, et al., “Bend-Insensitive and Low-Splice-Loss Optical fiber for Indoor Wiring in FTTH”, OFC 2004, ThI3 and M. B. Astruc, et al., “Trench-Assisted Profiles for Large-Effective-Area Single-Mode Fibers”, ECOC 2008, MO.4.B.1). For example, an optical fiber is proposed in the non patent literature 2 that has an effective core area that is increased to 120μm2 by optimizing the trench index profile.